1. Field of the Invention
The present invention relates to a marine propulsion system and, in particular, to an improved shifting mechanism.
2. Background of the Invention
Some conventional outboards motor include the following basic components: an engine, a crankshaft, a power transmission, a propeller, and a shifting mechanism. The engine may be contained within a protective cowling that includes an upper cover and a lower tray. Extending below the tray is a drive shaft housing that supports the engine and houses the drive shaft. Below the drive shaft housing is a lower unit that carries the transmission and the propeller. The transmission is located inside the lower unit and transmits power from the drive shaft to the propeller. Rotation of a shift rod, which depends into the transmission, shifts the transmission between gears.
The shift rod may be controlled by an operator. For instance, an actuator controlled by the operator may be coupled together with the shift mechanism and a shift lever. The shift lever, in turn, may be coupled to the shift rod such that circular rotation of the shift lever rotates the shift rod. Thus, the watercraft operator uses the actuator and the shift mechanism to selectively determine the gear of the transmission.
Shift mechanisms often include a shift position detection sensor to detect the circular motion of the shift lever. The sensor may be used to determine when the shift lever is in the neutral position. In such instances, the engine may be designed to start only when it receives a signal from the shift position sensor that the shift lever is in a neutral position. This helps to reduce abrupt movement upon ignition start-up. In addition, as disclosed in U.S. Pat. No. 5,050,461, the shift mechanism may also be configured to temporarily reduce the engine speed during shifting. This type of engine control aids shifting between gears.